Printing mechanism



April 13, 1937. A. w. MILLS PRINTING MECHANISM Filed Aug. ll, 1934 2 Sheets-Sheet 1 INVENTOR. //y BY ATTORNEY April 13, 1937- A. w. MILLS 2,076,740

PRINTING MECHANISM Filed Aug. l1, 1934 2 Sheets-Sheet 2 IN VEN TOR. ////a BY 4W/ZM A TTORNEY Patented Apr. 13, 1937 UNITED STATE-s PATENT oFFlcE national Business Machines Corporation, New

York, N. Y., a corporation of New-York Application August 11, 1934, serial No. 139,409 5 claims. (ci. 1111-93) This invention relates to accounting machines and more particularly to improvements in the printing mechanism thereof. Tabulating machines have heretofore been constructed in gen-4 eral with impositive driving mechanismfor positioning the type bars of the printing mechanism and where the number of 'type elements carried by a. type bar has not been more than are required for printing the digits-such impositive arrangement has been very satisfactory. In printing mechanisms where type bars are provided with sumcient type elements to print all the characters of the alphabet in addition to the numerical characters, the weight of the entire bar has necessarily been-increased and the inertia of the parts has tended to cause the type bar to lag behind the impositive driving mechanism. Other factors have also contributed towards interfering with the free movement of the type bars, such as stickiness, dust, oil, etc. With the present arrangement, positive means is provided for definitely and positively advancing the type bar to printing position so that upon the operation of the selecting mechanism timed to select a particular character for printing, the type element will definitely be at the printing position.

A further feature of the invention is the provision of a pair of contacts associated with each type bar selecting device which upon closure are adapted to complete a circuit through the adding magnet of an accumulator. This arrangement provides for a more definite relationship between the selection of a character for printing and the entry of a corresponding value into an accumulator.

In accordance with a modified form of the invention the type bar has light, intermediate bar which is not so readily susceptible to retardation as the heavier type bar. This intermediate bar is differentially positioned in accordance with the value printed and the type bar moves upward therewith and is in turn positioned thereby. Should the type bar lag during its advancing movement, it will nevertheless eventually come to rest with the proper character in printing position.

Various 'other objects and advantages of the invention will be obvious from the following particular description of one form of mechanisml embodying the invention or from an inspection of the accompanying drawings; and the inven- ,tion also constitutes certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

associated therewith a" In the drawings:

Fig. 1 is a detail section of a type bar and the operating mechanism therefor.

Fig. 2 isa detail of the operating cams kfor reciprocating the type bars.

The improved mechanism is shown in connection with a tabulator of the type shown in Patent No. 1,914,285, issued June 13, 1933 to J. R. Peirce, in which well known perforated records of the Hollerith type are successively fed past analyzing brushes I (Fig. 1) which, upon encountering a perforation in any one of the usual index point positions, will complete a circuit to print` ing magnet II which will attract its armature I2, drawing a call wire I3 to the right to cause latch I4 to release stopping pawl I5 so that one latter may rock in a clockwise direction under the influence of a spring I6.

The type bar structure comprises a type head I1 having type elements I8 thereon. The head I1 is carried by type bar I9 which is suitably mounted for vertical reciprocation. The lower end of the type bar is connected by alink 20 to an arm 2| which is pivoted at 22. Arm 2| has pivoted thereto at 23 a hook-shaped member 24 which is biased in a clockwise direction by a spring 25. Member 24 is adapted to engage the ledge of a crosshead 26 carried by arms 21 which are also pivoted at 22. Crosshead 26 is adapted to be oscillated by a pair of complementary cams 28 (Fig. 2)` which are carried by the drive shaft 29 of the machine and which rock a bell crank follower 30 carried on a rod 3|. Rod 3l also carries an arm 32 connected by a link 33 to an arm 34 on rod 35. Arms 36 supported on rod 35 have link connection 31 to the crosshead varms 21. As the crosshead 26 rocks in a clockwise direction synchronously with the movement of the record card past the analyzing brushes, the type bar I9 is elevated by virtue of the connection between the member 24 and the crosshead. Member 24 has pivoted thereto at 38 an intermediate bar 39 provided withfteeth 40 which, as the bar 39 moves upwardly with the member, successively pass the toe of pawl I as the correspondingly numbered index point positions of the record card pass theV analyzing brushes I0. Energization of the magnet II in response to a perforationin any position will trip pawl I5 and cause it to engage the correspondingly numbered tooth 40, thereby preventing further upward movement thereof. When such action takes place the continued upward movement of the crosshead 26 will cause the member 24 to cam away from the driving ledge of the crosshead and the further upward movement of the connected arm 2| and crosshead I9 will therefore be interru ted.

rm 2| has pivoted thereto a latching dog 4| which, when the arm 2| is thus released will engage one of the stepped notches 42 in a bar 43 to prevent retrograde movement of the associated parts.

' The above describes the manner in which the type elements I8 are positionedfor printing numerical characters. When alphabetic characters are to be printed, so-called zoning mechanism is brought into action which, by causing relative displacement between the type head I1 and type bar I9, will present 4the alphabetical characters tor printing position. The particular zoning mechanism forms no part of the present invention and reference may be had to my copending application Serial No. 634,690, iiled `September 24, 1932 wherein such zoning mechanism is shown and described.

After all the type bars have been positioned, the usual printing hammer 44 is operated to strike an impression therefrom. Thereafter the crosshead 26 is moved downwardly to cause restoration of the type bars. As it begins its downward movement, a cam 45 carried by shaft 29 will engage an arm 46 carried by rod `4`| and hold the latter in its rocked position while the type bars are being restored. Rod 41 carries a bail 43 which normally abuts the free ends of bars 43 to hold them in the position shown. 'I'he bars 43 are pivoted at 49 and urged against a stopping plate 5|) by springs 5|. During the restoring operation bars 49 are free to rock in' a clockwise direction and will do so under the influencev of the dogs 4| which, in. order that the arms 2| may move downwardly, will push bar 43 to the left and the dogs 4| will rock clockwise to their dotted line position, as shown in Fig. l, with their free ends pointing upwardly toward the left. c

'I'he travel of crosshead 26 during the restoring operation is of suillcient extent so that dogs 4| pass beyond the lowermost step of bar 43 and as the crosshead begins its next ascent, bail 48 will again be in position behind the bars 4I and the pawls 4| will be cammed by the lowermost step of bar 43 back to the position where the engaging end of the dog faces downwardly toward the left.

Member 24has connected toits depending arm 24a, a link 60 whose opposite end is attached to the free end of a pivoted arm 8|. A projection on arm 6| abuts against a blade of a pair of contacts 82 which upon closure complete a circuit to an adding magnet 63. The action is such that bar 39, the member 24 will be cammed in a counterclockwise direction and effect momentary closure of contacts 62 thus completing the adding circuit at a differential time depending upon the differential time at which the character is selected for printing.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modincation, it will ybe understood that ,various omisthrough link 60 willl sions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is 'as follows:

1. In a printing mechanism, atype carrier movable to a plurality of printing positions, a driving element for the same having an invariable movement. latching means for positively coupling the carrier to the driving element for movement thereby in one direction, a bar pivoted to said latching means, means for operating said bar at diil'erential times to enectunlatching of said carrier from said driving element, and constantly effective means for preventing retrograde movement of said carrier upon its release from the driving element.

2. In a printing mechanism, a type carrier movable to a plurality of printing positions. a driving element for the same having an invariable movement, latching means for coupling the carrier to the driving element for varying times during the advance movement of the element. electromagnetic means controlled by diii'erentially timed electrical impulses for controlling the latching means to eil'ect different durations of coupling between the carrier and the driving element, a spring urged latching bar for holding said carrier when released from the driving element, means for holding said bar in position and means for removing said holding means from said latching bar prior to the restoration of the carrier whereby the carrier will be lreleased for restoration.

3. In a printing mechanism, a type carrier,l

means for advancingsaid carrier, means for interrupting the same at differential'times to present different characters in position for printing, means for holding said carrier in position comprising a pivoted locking bar and a latching dog connected to the carrier and means for causing said bar to rock out of operative engagement with said dog to permit restoration of the carrier.

4. In a printing mechanism, a reciprocable type carrier, a pivoted operating arm, connected thereto, means for positively rocking said arm to reciprocate said carrier, means for disconnecting said arm from said rocking means to interrupt the movement of the carrier and means carried by the arm for holding the same in position upon its release from the rocking means.

5. In a printing mechanism,'a reciprocable type carrier, a pivoted operating arm connected thereto, an invariably movable driving element, a latch carried by said arm for connecting the same to said element for positive'y ymovement therewith whereby said ALBERT W. 

